Distal tears of the hamstring muscles: review of the literature and our results of surgical treatment

Surgical treatment of distal hamstring tendon injuries yield a higher return-to-sports rate: A systematic review

PURPOSE

The purpose of this study is to compare the patient-reported outcomes and return to sports of the conservative and surgical treatment of distal hamstring tendon injuries.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, two reviewers searched PubMed, Scopus and Virtual Health Library databases in January 2023. Clinical studies evaluating conservative or surgical management outcomes of distal hamstring tendon injuries were considered eligible for this systematic review if predefined criteria were fulfilled: (1) published in English or Spanish; (2) evaluated any of the following: patient-reported outcomes, return-to-sports rate (RTS-R) or return-to-sports time (RTS-T). Data were presented in tables using absolute values from individual studies and derived pooled percentages.

RESULTS

Eighteen studies were included for 67 patients and 68 distal hamstring tendon injuries. Initially, 39 patients (58.2%) underwent surgical treatment, whereas 28 (41.8%) were treated conservatively. Among conservative treatment patients, 15 failed and had to be operated on (53.6%), all with distal semitendinosus tendon injuries. Anchor fixation was the technique of choice in 20 lesions (36.4%), tenodesis in 16 (29.1%), tenectomy in 14 (25.5%) and sutures were preferred in five (9%). Thirteen out of 28 patients (46.4%) undergoing initial conservative treatment returned to sports at a mean of 3.6 months (range 1 week to 12 months), in contrast to surgical treatment, in which 36 out of 39 patients (92.3%) returned at a mean of 4.2 months (range 6 weeks to 12 months). Additionally, 14 of 15 patients (93.3%) converted to surgical treatment after failed conservative treatment returned to sports at a mean of 7.6 months after injury.

CONCLUSION

Initial surgical treatment of distal hamstring tendon injuries yields a high RTS-R (92.3%) at a mean of 4.2 months. Furthermore, 15 out of 28 patients (53.6%) initially treated conservatively had to be operated on, delaying the RTS-T (mean 7.6 months after injury) without affecting their RTS-R.

LEVEL OF EVIDENCE

IV.

Hamstring Injuries: A Current Concepts Review: Evaluation, Nonoperative Treatment, and Surgical Decision Making

The purpose of this current concepts review is to highlight the evaluation and workup of hamstring injuries, nonoperative treatment options, and surgical decision-making based on patient presentation and injury patterns. Hamstring injuries, which are becoming increasingly recognized, affect professional and recreational athletes alike, commonly occurring after forceful eccentric contraction mechanisms. Injuries occur in the proximal tendon at the ischial tuberosity, in the muscle belly substance, or in the distal tendon insertion on the tibia or fibula. Patients may present with ecchymoses, pain, and weakness. Magnetic resonance imaging remains the gold standard for diagnosis and may help guide treatment. Treatment is dictated by the specific tendon(s) injured, tear location, severity, and chronicity. Many hamstring injuries can be successfully managed with nonoperative measures such as activity modification and physical therapy; adjuncts such as platelet-rich plasma injections are currently being investigated. Operative treatment of proximal hamstring injuries, including endoscopic or open approaches, is traditionally reserved for 2-tendon injuries with >2 cm of retraction, 3-tendon injuries, or injuries that do not improve with 6 months of nonoperative management. Acute surgical treatment of proximal hamstring injuries tends to be favorable. Distal hamstring injuries may initially be managed nonoperatively, although biceps femoris injuries are frequently managed surgically, and return to sport may be faster for semitendinosus injuries treated acutely with excision or tendon stripping in high-level athletes.

London International Consensus and Delphi study on hamstring injuries part 2: operative management

The key indications for surgical repair of hamstring injuries (HSIs) remain unclear in the literature due to a lack of high-level evidence and expert knowledge. The 2020 London International Hamstring Consensus meeting aimed to highlight clear surgical indications and to create a foundation for future research. A literature review was conducted followed by a modified Delphi process, with an international expert panel. Purposive sampling was used with two rounds of online questionnaires and an intermediate round involving a consensus meeting. The initial information gathering (round 1) questionnaire was sent to 46 international experts, which comprised open-ended questions covering decision-making domains in HSI. Thematic analysis of responses outlined key domains, which were evaluated by a smaller international subgroup (n=15) comprising clinical academic sports medicine physicians, physiotherapists and orthopaedic surgeons in a consensus meeting. After group discussion of each domain, a series of consensus statements were prepared, debated and refined. A round 2 questionnaire was sent to 112 international hamstring experts to vote on these statements and determine level of agreement. The consensus threshold was set a priori at 70% agreement. Rounds 1 and 2 survey respondents were 35/46 (76%) and 99/112 (88.4%), respectively. The consensus group agreed that the indications for operative intervention included: gapping at the zone of tendinous injury (87.2% agreement) and loss of tension (70.7%); symptomatic displaced bony avulsions (72.8%); and proximal free tendon injuries with functional compromise refractory to non-operative treatment (72.2%). Other important considerations for operative intervention included: the demands of the athlete/patient and the expected functional outcome (87.1%) based on the anatomy of the injury; the risk of functional loss/performance deficit with non-operative management (72.2%); and the capacity to restore anatomy and function (87.1%). Further research is needed to determine whether surgery can reduce the risk of reinjury as consensus was not reached within the whole group (48.2%) but was agreed by surgeons (70%) in the cohort. The consensus group did not support the use of corticosteroids or endoscopic surgery without further evidence. These guidelines will help standardise treatment of HSIs, specifically the indications and decision-making for surgical intervention.

Isolated complete rupture of distal biceps femoris tendon following a motor vehicle accident: A case report and review of the literature

Isolated complete ruptures of the distal biceps femoris tendon are rare injuries. To our knowledge, very few cases have been reported in English literature. We present the case of a young man who complained of pain on the posterolateral corner of the knee after a motor vehicle accident. Clinical examination and MRI findings revealed a complete rupture at the musculotendinous junction of distal biceps femoris tendon. We describe the surgical treatment performed, and the clinical outcome.

Distal Biceps Femoris Tendon Tear in an Active-Duty Soldier: A Case Report and Review of the Literature

Distal hamstring injuries and tendon ruptures are rarer than their proximal counterparts, and literature on the management of these injuries is limited. We present a case report of an active-duty soldier who sustained an intratendinous rupture isolated to the long head of the biceps femoris, as well as a summary of the available evidence on this subject matter. A combined end-to-end repair with partial tenodesis to the intact short head allowed the patient a near-full return to military duties at 5 months postoperatively. Surgery combined with diligent, supervised rehabilitation may be effective in returning patients with intratendinous distal biceps femoris tendon tears to athletic lifestyles.

Distal Hamstring Muscle Injuries

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Distal hamstring muscle injuries, although relatively uncommon, can potentially lead to substantial morbidity in athletes; prolonged rehabilitation times and high rates of reoccurrence have been documented.

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Overall, magnetic resonance imaging is considered the "gold standard" for evaluation of hamstring injuries because it allows assessment for concomitant pathology and can clarify return-to-sport timelines.

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Complete tears of the distal biceps femoris and semimembranosus muscles respond well to surgical repair, whereas complete tears of the distal semitendinosus can be successfully treated nonoperatively or with surgical resection.

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Future research may be necessary to further optimize treatment of these injuries and to determine the efficacy of biologic adjuvant therapy.

Efficacy of Surgical Tenodesis for Treatment of Distal Semitendinosus Hamstring Tendon Injuries

Background:

Understanding the optimal management of distal semitendinosus hamstring injuries is critical for reducing pain, restoring preinjury function, maintaining knee stability, improving hamstring muscle strength, and minimizing the risk of complications and recurrence. To our knowledge, the outcomes of surgical tenodesis for distal semitendinosus hamstring injuries have not been previously reported.

Hypothesis:

Surgical tenodesis for injuries of the semitendinosus would enable return to preinjury level of sport with low risk of recurrence.

Study Design:

Case series; Level of evidence, 4.

Methods:

This prospective single-surgeon study included 13 professional athletes (12 men, 1 woman; mean age, 32 ± 8.2 years; mean body mass index, 26.7 ± 3.9 kg/m²) undergoing treatment for distal semitendinosus hamstring injuries with primary tenodesis to the distal semimembranosus. Indications for surgical tenodesis included distal semitendinosus tendon avulsion injury (n = 8) or residual tendon instability and hamstring weakness after semitendinosus graft harvest for anterior cruciate ligament reconstruction (n = 5). All study patients underwent a standardized postoperative rehabilitation program. The primary outcome was defined as time for return to sporting activity. Secondary outcomes were patient satisfaction, injury recurrence, and complications. The mean follow-up time was 17 months (range, 12-24 months) from date of surgery.

Results:

All study patients returned to their preinjury level of sporting activity. The mean time from the surgical intervention to return to full sporting activity was 15 ± 4.6 weeks. At 1-year follow-up, all study patients were still participating at their preinjury level of sporting activity, and 12 patients (92%) were very satisfied and 1 patient (8%) was satisfied about the outcomes of their surgery. No study patients had recurrence of the primary injury. No surgical complications, injury recurrence, or reoperations were observed within the follow-up period.

Conclusion:

Early return to sporting activity was seen after surgical tenodesis for distal semitendinosus hamstring injuries after acute trauma or residual symptoms following previous hamstring graft harvest, with high levels of patient satisfaction and low risk of recurrence at short-term follow-up.

Injuries in Muscle-Tendon-Bone Units: A Systematic Review Considering the Role of Passive Tissue Fatigue

Background:

Low-cycle fatigue damage accumulating to the point of structural failure has been recently reported at the origin of the human anterior cruciate ligament under strenuous repetitive loading. If this can occur in a ligament, low-cycle fatigue damage may also occur in the connective tissue of muscle-tendon units. To this end, we reviewed what is known about how, when, and where injuries of muscle-tendon units occur throughout the body.

Purpose:

To systematically review injuries in the muscle-tendon-bone complex; assess the site of injury (muscle belly, musculotendinous junction [MTJ], tendon/aponeurosis, tendon/aponeurosis–bone junction, and tendon/aponeurosis avulsion), incidence, muscles and tendons involved, mechanism of injury, and main symptoms; and consider the hypothesis that injury may often be consistent with the accumulation of multiscale material fatigue damage during repetitive submaximal loading regimens.

Methods:

PubMed, Web of Science, Scopus, and ProQuest were searched on July 24, 2019. Quality assessment was undertaken using ARRIVE, STROBE, and CARE (Animal Research: Reporting In Vivo Experiments, Strengthening the Reporting of Observational Studies in Epidemiology, and the Case Report Statement and Checklist, respectively).

Results:

Overall, 131 studies met the inclusion criteria, including 799 specimens and 2,823 patients who sustained 3,246 injuries. Laboratory studies showed a preponderance of failures at the MTJ, a viscoelastic behavior of muscle-tendon units, and damage accumulation at the MTJ with repetitive loading. Observational studies showed that 35% of injuries occurred in the tendon midsubstance; 28%, at the MTJ; 18%, at the tendon-bone junction; 13%, within the muscle belly and that 6% were tendon avulsions including a bone fragment. The biceps femoris was the most injured muscle (25%), followed by the supraspinatus (12%) and the Achilles tendon (9%). The most common symptoms were hematoma and/or swelling, tenderness, edema and muscle/tendon retraction. The onset of injury was consistent with tissue fatigue at all injury sites except for tendon avulsions, where 63% of the injuries were caused by an evident trauma.

Conclusion:

Excluding traumatic tendon avulsions, most injuries were consistent with the hypothesis that material fatigue damage accumulated during repetitive submaximal loading regimens. If supported by data from better imaging modalities, this has implications for improving injury detection, prevention, and training regimens.

Distal avulsion of reconstituted hamstring tendons

PURPOSE

Hamstring tendon autograft (semitendinosus and gracilis) is the most commonly used graft in anterior cruciate ligament (ACL) reconstruction. Distal hamstring tendons avulsion is a rare condition, and this paper describes a previously unreported injury, local management of this rare injury pattern, and the existing literature regarding treatment options.

METHODS

Two cases are presented of distal hamstring avulsion from the tibia of reconstituted tendons, together with additional 12 cases of distal hamstrings tendon avulsion. Functional outcomes following treatment of this injury are presented, together with a literature review of management options.

RESULTS

Early surgical reattachment using suture anchor fixation was performed and excellent results were achieved in 93% of cases (13 out of 14 patients). Patient-reported outcome measures demonstrated a median Marx score 14.5 (IQR 4) and median SHORE score 34.5 (IQR 4). The mean time to surgery was 22 days (range 5-60), with mean time to return to sport at pre-injury level 5.5 months (range 2.5-12).

CONCLUSIONS

Distal hamstring tendon avulsion is a rare condition, with no consensus regarding optimal management options. Acute surgical repair leads to excellent results, with a return to pre-injury level of sporting activity.

LEVEL OF EVIDENCE

IV.

Surgical Repair of Distal Biceps Femoris Avulsion Injuries in Professional Athletes

Background

Understanding the optimal management of distal biceps femoris avulsion injuries is critical for restoring preinjury function, restoring hamstring muscle strength, increasing range of motion, and minimizing risk of complications and recurrence. Due to the rarity of these injuries, prognosis and outcomes within the literature are limited to case reports and small case series.

Purpose

To assess the effect of surgical repair for acute distal avulsion injuries of the biceps femoris tendon on (1) return to preinjury level of sporting function and (2) time to return to preinjury level of sporting function, patient satisfaction, and complications.

Study Design

Case series; Level of evidence, 4.

Methods

This prospective single-surgeon study included 22 elite athletes (18 men [82%], 4 women [18%]; mean age, 26 years; age range, 17-35 years; mean body mass index, 25.3 ± 4.1 kg/m²) undergoing primary suture anchor repair of avulsion injuries of the distal biceps femoris confirmed on preoperative magnetic resonance imaging. Predefined outcomes relating to time for return to sporting activity, patient satisfaction, complications, and injury recurrence were recorded at regular intervals after surgery. Minimum follow-up time was 12 months (range, 12.0-26.0 months) from the date of surgery.

Results

The mean time from injury to surgical intervention was 12 days (range, 2-28 days). All study patients returned to their preinjury level of sporting activity, predominately professional soccer or rugby. Mean time from surgical intervention to return to full sporting activity was 16.7 ± 8.7 weeks. At 1- and 2-year follow-up, all study patients were still participating at their preinjury level of sporting activity. There was no incidence of primary injury recurrence, and no patients required further operation to the biceps origin.

Conclusion

Surgical repair of acute avulsion injuries of the distal biceps femoris facilitated early return to preinjury level of function with low risk of recurrence, low complication rate, and high patient satisfaction in elite athletes. Suture anchor repair of these injuries should be considered a reliable treatment option in athletes with high functional demands to permit an early return to sport with restoration of hamstring strength.

Tears of Biceps Femoris, Semimembranosus, And Semitendinosus are Not Equal-A New Individual Muscle-Tendon Concept in Athletes

Objectives:

Hamstring injuries are common and can now be accurately diagnosed. In addition, novel surgical indications have been introduced. However, evidence-based guidelines on the hamstring injuries in management of top-level athletes are missing.

Methods:

The management methods and outcomes of treatment are classically based on relatively small case series. We discuss a novel concept based on the fact that each tendon of the hamstrings muscle should be managed in an individual fashion. Furthermore, suitable indications for hamstring surgery in athletes are introduced.

Results:

The present study introduces modern treatment principles for hamstring injury management. Typical clinical and imagining findings as well as surgical treatment are presented based on a critical review of the available literature and personal experience.

Conclusions:

Hamstring injuries should not be considered to be all equal given the complexity of this anatomical region: The three separate tendons are different, and this impacts greatly on the decision-making process and outcomes in athletes.

Distal biceps femoris avulsions: Associated injuries and neurological sequelae

BACKGROUND

The aim of this study was to describe associated injuries in cases of distal biceps femoris avulsions (DBFA) as well as the incidence of neurological injury and radiographic abnormalities of the common peroneal nerve (CPN).

METHODS

A retrospective chart review was conducted of patients presenting to our office or trauma center with DBFA injuries. Demographic data was obtained as well as mechanism of injury. Assessment of concomitant injuries and presence of neurologic injury was completed via chart review and magnetic resonance imaging (MRI) review. The CPN was evaluated for signs of displacement or neuritis.

RESULTS

Sixteen patients were identified (mean age-at-injury 28.6 years, 87.5% male) with DBFA. Three patients (18.8%) sustained their injuries secondary to high energy trauma while 13 (81.3%) had injuries secondary to lower energy trauma. Nine patients (56.3%) initially presented with CPN palsy. All patients presenting with CPN palsy of any kind were found to have a displaced CPN on MRI and no patient with a normal nerve course had a CPN palsy.

CONCLUSIONS

This case series demonstrates a strong association between DBFA and CPN palsy as well as multi-ligamentous knee injury (MLKI). These injuries have a higher rate of CPN palsy than that typically reported for MLKI. Furthermore, these findings suggest that CPN displacement on MRI may be a clinically significant indicator of nerve injury. LOE: IV.

Management of hamstring injuries: current concepts review

Injuries to the hamstring muscle complex are common in athletes, accounting for between 12% and 26% of all injuries sustained during sporting activities. Acute hamstring injuries often occur during sports that involve repetitive kicking or high-speed sprinting, such as American football, soccer, rugby, and athletics. They are also common in watersports, including waterskiing and surfing. Hamstring injuries can be career-threatening in elite athletes and are associated with an estimated risk of recurrence in between 14% and 63% of patients. The variability in prognosis and treatment of the different injury patterns highlights the importance of prompt diagnosis with magnetic resonance imaging (MRI) in order to classify injuries accurately and plan the appropriate management. Low-grade hamstring injuries may be treated with nonoperative measures including pain relief, eccentric lengthening exercises, and a graduated return to sport-specific activities. Nonoperative management is associated with highly variable times for convalescence and return to a pre-injury level of sporting function. Nonoperative management of high-grade hamstring injuries is associated with poor return to baseline function, residual muscle weakness and a high-risk of recurrence. Proximal hamstring avulsion injuries, high-grade musculotendinous tears, and chronic injuries with persistent weakness or functional compromise require surgical repair to enable return to a pre-injury level of sporting function and minimize the risk of recurrent injury. This article reviews the optimal diagnostic imaging methods and common classification systems used to guide the treatment of hamstring injuries. In addition, the indications and outcomes for both nonoperative and operative treatment are analyzed to provide an evidence-based management framework for these patients. Cite this article: Bone Joint J 2020;102-B(10):1281-1288.

A rare case of isolated traumatic avulsion of the pes anserinus tendon

Complete rupture of the conjoint pes anserinus tendon is rare, and isolated rupture without injury to associated structures has not been previously reported in the literature. A case of complete isolated rupture of the pes anserinus tendon is described in a young, healthy male. The non-specific nature of the presentation and rarity of the condition makes diagnosis from history and examination alone challenging. Magnetic resonance imaging was critical in making the correct diagnosis and excluding other potential-associated injuries with the diagnosis confirmed intraoperatively. The patient underwent surgical repair and rehabilitation and made significant progress. The diagnosis may be overlooked on a routine knee MRI, particularly in the absence of other associated injuries. An untreated injury may result in a poor outcome for the patient, with chronic pain and reduced function. Hence it is important to consider it in traumatic injuries to the region, with a view for an extended scan to visualise the full extent of the pes tendons to their insertion, particularly when there is high fluid signal in the popliteal fossa along the semitendinosus.

Comparison of Regional Hamstrings Activation During Resistance Exercises in Females With Prior Athletic Experience

CONTEXT

Within each hamstring muscle, there are segments with separate nerve innervation. However, a better understanding of activation levels within these regions during resistance exercise could lead to region-specific training for improved performance and injury prevention.

OBJECTIVE

To compare muscle activation levels within regions of the hamstrings during various resistance exercises.

DESIGN

Within-subjects repeated measures.

SETTING

Biomechanics laboratory.

PARTICIPANTS

Eighteen young adult females with previous competitive sport participation and resistance training experience.

INTERVENTION

One set of 3 repetitions with an 8RM load on the bilateral squat, modified single-leg squat, stiff-legged dead lift, and leg curl (LC).

MAIN OUTCOME MEASURES

Normalized surface electromyography of 4 hamstring regions (proximal-medial, proximal-lateral, distal-medial, and distal-lateral).

RESULTS

For LC only, electromyography measures for the proximal-lateral location were significantly lower than for the distal-lateral, t18 = 5.6, P < .001, and proximal-medial, t18 = 2.4, P = .01 locations for concentric contractions. Similar results were observed for eccentric contractions. No other exercises revealed regional activation differences. When comparing the pooled proximal (medial and lateral) region across exercises, the LC demonstrated significantly greater activation than the modified single-leg squat, t18 = 5.20, P < .001, stiff-legged dead lift, t18 = 7.311, P < .001, and bilateral squat, F3,54 = 49.8, P < .001. Similar significantly greater levels were also found during the LC for the pooled distal, medial, and lateral regions. In addition, the modified single-leg squat electromyography was significantly greater at all regions in comparison with the stiff-legged dead lift and bilateral squat.

CONCLUSIONS

The data did not reveal consistent regional differences within the different exercises included in this study. However, the data indicate that the LC produces the highest hamstring activation in all regions across exercises. Inclusion of single-joint knee-flexion exercises would appear to be most beneficial for hamstrings development in a resistance-training program.

Surgical Repair of Distal Musculotendinous T Junction Injuries of the Biceps Femoris

BACKGROUND

Nonoperative management of injuries to the distal musculotendinous T junction of the biceps femoris is associated with variable periods of rehabilitation and high risk of recurrence. To our knowledge, the efficacy of operative treatment in patients with these acute injuries has not been previously reported.

HYPOTHESIS

Surgical repair of injuries to the distal musculotendinous T junction of the biceps femoris would enable return to preinjury level of sport with low risk of recurrence.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

This prospective single-surgeon study included 34 professional athletes (mean age, 26.4 ± 3.1 years; 31 male [91.2%]; 3 female [8.8%]; body mass index, 25 ± 2.0 kg/m²) undergoing primary surgical repair of acute injuries to the distal musculotendinous T junction of the biceps femoris. All study patients underwent a standardized postoperative rehabilitation program. Predefined study outcomes relating to time for return to sporting activity, patient satisfaction, range of motion, hamstring muscle strength, passive range of motion, functional progress, and complications were recorded at regular intervals after surgery. Mean follow-up time was 28.4 months (range, 24.0-36.3 months) from date of surgery.

RESULTS

All study patients returned to their preinjury level of sporting activity. Mean time from surgical repair to full sporting activity was 11.7 ± 3.6 weeks. No patients had recurrence of the primary injury. At 1-year follow-up, 18 patients (52.9%) were very satisfied and 16 patients (47.1%) were satisfied with the outcomes of their surgery. At 3 months after surgery, patients had improved mean passive straight leg raise (69.7° ± 11.7° vs 24.1° ± 7.4°; P < .001); increased mean isometric hamstring muscle strength at 0° (93.1% ± 5.4% vs 63.1% ± 7.7%; P < .001), 45° (76.8% ± 9.7% vs 24.8% ± 8.3%; P < .001), and 90° (96.4% ± 3.9% vs 85.6% ± 5.9%; P < .001); higher mean lower extremity functional scores (64.5 ± 4.5 vs 27.2 ± 5.4; P < .001); and improved mean Marx Activity Rating Scale scores (10.7 ± 2.7 vs 2.2 ± 2.1; P < .001) compared with preoperative values. High patient satisfaction and functional outcome scores were maintained at 1 and 2 years after surgery.

CONCLUSION

Surgical repair of acute injuries to the distal musculotendinous T junction of the biceps femoris is associated with high patient satisfaction, increased muscle strength, improved functional outcome scores, and high return to preinjury level of sporting activity with low risk of recurrence at short-term follow-up.

Return to Collegiate Hockey After Repair of Chronic Biceps Femoris Tendon Transection at the Knee: A Case Report

CASE

A 22-year-old man sustained complete transection of his right distal biceps femoris tendon by a hockey skate. He experienced persistent pain and disability, symptoms of peroneal neuritis, and an inability to return to hockey. At 3-months postinjury, he underwent biceps femoris repair and peroneal neurolysis. At 9-months postoperatively, the patient returned to full activity and played a full season collegiate hockey.

CONCLUSIONS

Isolated distal biceps femoris transection is rare and may be associated with peroneal neuritis. Primary repair and peroneal neurolysis is a viable treatment option (even 3 months postinjury), with satisfactory outcomes and full return to high-level activity.

Electrophysiological Changes After Human Muscle Tear: A Potential Confounder

The goal of this prospective electrophysiologic study is to describe the chronological electromyographic findings observed in a human gastrocnemius muscle after a traumatic tear. A 30-yr-old man sustained a tear of the medial gastrocnemius. Needle electromyography was performed serially at 5, 15, and 26 wks after injury, with the contralateral gastrocnemius muscle serving as a control. Audiovisual recordings of the studies were analyzed in a blinded manner. Five weeks after injury, the affected gastrocnemius displayed increased insertional activity on electromyography. By 15-wk postinjury, insertional activity had diminished. However, motor unit action potentials showed chronic neurogenic morphological changes not previously observed. These changes persisted 26 wks after injury. The study findings reveal a chronological trajectory of increased insertional activity followed by reinnervation changes in a human muscle after local trauma, paralleling a course previously observed in a rat model. Electrodiagnosticians unaware of this phenomenon are at risk for making erroneous interpretations when examining patients with a history of muscle trauma.

Damage to or Injury of the Distal Semitendinosus Tendon During Sporting Activities: A Systematic Review

BACKGROUND

Isolated distal semitendinosus tears and avulsions sustained during sporting activities are uncommon.

QUESTION/PURPOSES

We sought to systematically review the literature to identify athletes sustaining distal semitendinosus tears and avulsions during sporting activities and to better understand injury mechanisms, management, and return-to-sport timing.

METHODS

PubMed, Biosis Previews, SPORTDiscus, PEDro, and EMBASE databases were searched from January 1970 to January 2018 using the search terms distal hamstring, semitendinosus, sport, athlete, tear, rupture, and avulsion. Inclusion criteria were studies documenting (1) isolated, complete distal semitendinosus tears and avulsions during sporting activity, (2) injury management, and (3) athlete outcome. Exclusion criteria were studies reporting (1) partial tears, (2) injuries from non-sporting activities, or (3) athlete sustaining injury with concomitant injuries about the knee. Sporting activities, tear location, management strategy, time from injury to surgery, and return-to-sport timing were analyzed. Statistical analysis was used to evaluate return-to-sport timing based on treatment type and tear location.

RESULTS

Four studies met the inclusion criteria, comprising a total of 23 cases of complete, isolated distal semitendinosus avulsions or tears. Injuries were sustained predominantly while running or sprinting and most commonly were avulsions off the tibia. Injuries were treated surgically in 70% of cases. Overall time to return to sport was 2.5 ± 1.4 months with athletes treated conservatively returning significantly more quickly (1.5 ± 0.8 months) than athletes undergoing surgery (3.0 ± 1.3 months). Return-to-sport time was significantly shorter in athletes with complete avulsions (2.2 ± 1.3 months) than in those sustaining tears at the musculotendinous junction (3.8 ± 0.8 months). No significant correlation between time to surgery and return-to-sport time was appreciated.

CONCLUSION

Isolated, complete distal semitendinosus tears and avulsions remain infrequently reported during sporting activities and, in this review, occurred predominantly during non-contact activity. Athletes treated conservatively were found to return to sport more quickly, although additional studies are needed to determine the clinical relevance of treatment option, tear location, and concurrent injuries.

Isolated Complete Rupture of the Biceps Femoris Insertion: A Surgical Repair Technique Manuscript

Isolated rupture of the distal biceps femoris insertion is rare. Current literature offers limited case reports and outcome measures after surgical management. We describe a knotless suture anchor fixation technique for this tear pattern. At surgery, the retracted biceps tendon and insertion site is debrided to healthy tissue, FiberTape suture (Arthrex) is passed in a Kracków fashion through the tendon, and the 2 ends of the suture are brought down to a SwiveLock anchor (Arthrex) at the anatomic insertion. FiberWire sutures (Arthrex) from the anchor are brought over the remnant stump, completing the repair.

Anatomy of proximal attachment, course, and innervation of hamstring muscles: a pictorial essay

Hamstring injuries are very common in sports medicine. Knowing their anatomy, morphology, innervation, and function is important to provide a proper diagnosis, treatment as well as appropriate prevention strategies. In this pictorial essay, based on anatomical dissection, the detailed anatomy of muscle-tendon complex is reviewed, including their proximal attachment, muscle course, and innervation. To illustrate hamstrings' role in the rotational control of the tibia, the essay also includes the analysis of their biomechanical function.Level of evidence V (expert opinion based on laboratory study).

Isolated Tearing and Avulsion of the Distal Biceps Femoris Tendon During Sporting Activities: A Systematic Review

Background:

Isolated tearing and avulsions of the distal biceps femoris sustained during sporting activities are uncommon.

Purpose:

To systematically review the literature to identify distal biceps femoris tears and avulsions experienced during sporting activities to determine injury prevalence, sporting activities/mechanisms, management, and time to return to sport.

Study Design:

Systematic review; Level of evidence, 4.

Methods:

A systematic review was conducted investigating studies published between January 1970 and December 2017 that reported on athletes sustaining tears and avulsions of the distal biceps femoris during sporting activity. The review followed the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines and used the PubMed, Biosis Previews, SPORTDiscus, PEDro, and EMBASE databases. Inclusion criteria were studies reporting on (1) partial or complete tears and avulsions of the distal biceps femoris with documented sporting activity causing injury, (2) injury management (operative vs nonoperative), and (3) patient outcome. Exclusion criteria consisted of studies reporting on (1) distal biceps femoris injuries without tearing, (2) injuries secondary to nonsporting activities (mechanical falls, trauma), (3) concomitant injuries to adjacent structures about the knee, and (4) studies not reporting injury management or patient outcomes. Sporting activities, injury characteristics, management, and time to return to sport were analyzed.

Results:

A total of 22 athletes with isolated distal biceps femoris tears or avulsions were identified. Injuries were predominantly associated with noncontact knee hyperextension with concurrent hip flexion during soccer or track and field, most commonly isolated to the musculotendinous junction. Injuries were treated surgically in 91% (20/22) of athletes. Mean (±SD) overall time to return to sport was 4.9 ± 3.3 months, and for athletes who underwent operative repair, there were no significant postoperative differences based on injury location (musculotendinous junction vs avulsion, P = .25) or injury severity (partial vs complete injury, P = .13).

Conclusion:

Isolated distal biceps femoris injuries occurred primarily via noncontact mechanisms. The majority of cases were treated surgically, with successful return to sport at preinjury levels. No significant difference in return to sport was appreciated based on injury location or severity. Further studies are necessary to determine the impact of treatment method.

Tendon Excision Following Distal Semitendinosus Injury in the Elite Athlete: A Surgical Technique

BACKGROUND

Hamstring injuries can present in numerous forms, some of which can lead to persistent pain, loss of function, and delay in return to sport. Although most are treated conservatively, proximal and distal tendon avulsion injuries have become more commonly treated with surgery. Distal semitendinosus avulsion injuries have been largely reported in the elite athlete population. While conservative management has been utilized, failure in this group can significantly impact a future career.

PURPOSE

The purpose of the manuscript is to describe our approach of surgical tendon excision for distal semitendinosus injury in an elite athlete.

METHODS

We highlight a two-incision technique to isolate the avulsed tendon, followed by exteriorization and tendon excision. In addition, we provide insight on clinical and imaging findings to help guide management.

RESULTS

This technique provides a reliable and effective surgical option for managing these rare injuries of the distal semitendinosus, along with outlining rehabilitation goals in the postoperative period.

CONCLUSION

In this setting, we present a detailed surgical technique to excise the injured distal semitendinosus tendon to promote recovery and potentially allow for earlier return to play.

Investigation and management of an isolated complete distal avulsion of semitendinosus

A 34-year-old male patient presented with right-sided posteromedial knee pain following an attempted tackle during a soccer match. MRI revealed that the semitendinosus (ST) tendon had completely avulsed from its distal insertion site. The patient was initially managed conservatively but eventually required surgery due to ongoing posteromedial knee pain. Surgical management was achieved through tenodesis of ST to gracilis. Postsurgery, the posteromedial knee pain had been alleviated, and following physiotherapy the patient regained a good range of motion.

Popeye sign of the semimembranosus

A 23-year-old amateur football player presented 9 months after acute onset of severe pain and a lump in the posterior right knee whilst lifting a heavy box. He had been unable to return to playing football or climbing the stairs. Clinically, a Baker's cyst was suspected. MRI scan, the imaging modality of choice, was essentially normal. A subsequent ultrasound (US) scan demonstrated abnormal dynamic bunching of the muscle fibres at the distal semimembranosus myotendinous junction on resisted isometric contraction, most likely due to a previous tear isolated to the distal myotendinous junction. The proximal biceps femoris tendon is the most commonly injured part of the hamstring. Distal semimembranosus tears are far less common. Semimembranosus tendinopathy is an uncommon cause of chronic knee pain that is probably underdiagnosed and inadequately treated. In this case, the distal semimembranosus injury was occult on MRI because the features were only apparent with dynamic imaging, something that is not routinely part of musculoskeletal MRI protocols, whereas real-time imaging is easily performed with US. MRI is thought to be more sensitive than US for follow-up imaging of healing hamstring injuries; however, this case highlights the usefulness of dynamic imaging of muscle injuries with US. We propose that the abnormal dynamic muscle bulge on the US image would be aptly described as a "Popeye sign," which, to our knowledge, has not previously been reported in any other anatomical location than the long head of the biceps brachii in the published literature.

Central Tendon Injuries of Hamstring Muscles: Case Series of Operative Treatment

Background:

As compared with injuries involving muscle only, those involving the central hamstring tendon have a worse prognosis. Limited information is available regarding the surgical treatment of central tendon injuries of the hamstrings.

Purpose:

To describe the operative treatment and outcomes of central tendon injuries of the hamstrings among athletes.

Study Design:

Case series; Level of evidence, 4.

Methods:

Eight athletes (6 top level, 2 recreational) with central hamstring tendon injuries underwent magnetic resonance imaging and surgical treatment. The indication for surgery was recurrent (n = 6) or acute (n = 2) central hamstring tendon injury. All patients followed the same postoperative rehabilitation protocol, and return to play was monitored.

Results:

Magnetic resonance imaging found a central tendon injury in all 3 hamstring muscles (long head of the biceps femoris, semimembranosus, and semitendinosus) with disrupted tendon ends. In acute and recurrent central tendon injuries, full return to play was achieved at 2.5 to 4 months. There were no adverse events during follow-up.

Conclusion:

Central tendon injuries of the hamstrings can be successfully repaired surgically after acute and recurrent ruptures.

A Biomechanical Assessment of Biceps Femoris Repair Techniques

Background:

Knee injuries encountered in clinical practice can involve avulsions of the biceps femoris from the fibula and proximal tibia. Advances in tendon repair methods now allow for repairs with increased surface areas using modern suture anchor techniques. Despite descriptions of repair techniques, there are no biomechanical studies on the biceps femoris for comparison.

Purpose/Hypothesis:

The objective of this controlled laboratory study was to determine the failure load of the native biceps femoris distal insertion and to evaluate modern repair techniques. Our hypothesis was 2-fold: (1) Suture repairs to the tibia and fibula would perform better on tensile testing than repairs to the fibula alone, and (2) complex bridge repairs, similar to those frequently used in rotator cuff surgery, would perform better on tensile testing than simple repairs.

Study Design:

Controlled laboratory study.

Methods:

A total of 40 paired, fresh-frozen cadaveric specimens were dissected, identifying the biceps femoris and its insertion on the proximal tibia and fibula. The native biceps femoris footprint was left intact in 8 specimens and tested to failure on a uniaxial materials testing machine evaluating tensile properties, while in the other 32 specimens, the biceps femoris insertion was dissected using a No. 15 scalpel blade, underwent repair, and was then tested to failure on a uniaxial materials testing machine evaluating tensile properties. Four repair constructs were evaluated, with 8 specimens allocated for each: construct 1 involved a simple repair (ie, passing suture through tissue in a running Krackow fashion and tying at the anchor site) to the fibula with 2 suture anchors, construct 2 involved a simple repair to the fibula and tibia with 3 suture anchors, construct 3 was a fibular repair with a tibial suture bridge involving the fibula and tibia and 3 suture anchors, construct 4 involved a transosseous repair through the fibula and 1 suture anchor on the tibia. Analysis of variance was used to evaluate for significance of the mean failure load and stiffness between groups.

Results:

The mean (±95% CI) failure loads were the following: native biceps femoris, 1280 ± 247.0 N; simple fibular repair, 173 ± 84.6 N; simple fibular and tibial repair, 176 ± 48.1 N; fibular repair with tibial suture bridge, 191 ± 78.5 N; and transosseous repair, 327 ± 66.3 N. The mean stiffness values were the following: native, 46 ± 13.0 N/mm; simple fibular repair, 16 ± 5.1 N/mm; simple fibular and tibial repair, 14 ± 5.4 N/mm; fibular repair with tibial suture bridge, 13 ± 2.8 N/mm; and transosseous repair, 15 ± 2.5 N/mm. Interconstruct comparison of failure loads revealed no statistical difference between constructs utilizing anchors alone. The transosseous repair showed a significant difference for the failure load when compared with each anchor repair construct (P = .02, .02, and .04 for constructs 1, 2, and 3, respectively). Interconstruct comparison of stiffness revealed no statistical difference between all constructs (P > .86). None of the repair techniques re-created the failure load or stiffness of the native biceps femoris tendon (P = .02).

Conclusion:

In this biomechanical study, no difference was found between the mean failure loads of different biceps femoris repair constructs involving suture anchors alone and No. 2 braided polyester and ultra–high-molecular-weight polyethylene suture. A technique involving transosseous fibular tunnels and 2-mm suture tape illustrated a greater mean failure load than repairs relying on suture anchors for fixation.

Clinical Relevance:

Understanding the tensile performance of biceps femoris repair constructs aids clinicians with preoperative and intraoperative decisions. Current biceps femoris repair techniques do not approximate the native strength of the tendon. A transosseous style of repair offers the highest failure load.

Operative treatment for the painful posterior thigh after hamstring autograft harvesting

Background

Semitendinosus (ST) is widely used autograft in anterior cruciate ligament reconstructions (ACLR). Although tendon harvesting is a common procedure, some patients exhibit pain, cramping and dysfunctional at posterior thigh after the ACLR. The formation of the newly regenerated neotendon could be compromised by a new injury or too rapid rehabilitation. We present this clinical entity and the developed surgical technique and share our experience in treatment of these patients.

Methods

Ten patients underwent operation where the harvested, retracted and loose muscle (9 ST, 1 gracilis) was reattached again. The delay to the diagnosis and the outcome of the procedure were recorded. Cases were followed and magnetic resonance images (MRI) were included from 2 cases for the demonstration of postoperative healing.

Results

Six ST and the gracilis patients with prolonged symptoms had good results and returned to their normal activity level. Preoperative MRI showed increased signal intensity and edema of the harvested and retracted muscles as the sign of compromised healing of the neotendon. Postoperatively, these MRI findings were resolved.

Conclusions

In high activity level patients with chronic posterior thigh pain and cramping of the harvested muscle, the stabilization procedure of the poorly healed muscle belly could lead to beneficial outcome.

Level of evidence

IV. Case series.

Entrapment of Common Peroneal Nerve by Surgical Suture following Distal Biceps Femoris Tendon Repair

We describe entrapment of the common peroneal nerve by a suture after surgical repair of the distal biceps femoris tendon. Complete rupture of the distal biceps femoris tendon of a 16-year-old male athlete was surgically repaired. Postoperative common peroneal nerve palsy was evident, but conservative treatment did not cause any neurological improvement. Reexploration revealed that the common peroneal nerve was entrapped by the surgical suture. Complete removal of the suture and external neurolysis significantly improved the palsy. The common peroneal nerve is prone to damage as a result of its close proximity to the biceps femoris tendon and it should be identified during surgical repair of a ruptured distal biceps femoris tendon.

Patterns of Hamstring Muscle Tears in the General Population: A Systematic Review

Background

Hamstring tears are well recognised in the sporting population. Little is known about these injuries in the general population.

Purpose

Evaluating the rates, patterns and risk factors of non-sporting hamstring tears, compared to sporting related hamstring tears.

Data Sources

MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (1989–2015).

Study Selection

Studies reporting patients with a grade 2 or 3 hamstring muscle tear, identified clinically, confirmed by MRI imaging or direct visualisation during surgical exploration.

Data Synthesis

144 sets of linked data were extracted for analysis. Most injuries were in males (81.3%), where mean age at injury was lower (30.2, 95% CI 29.1–31.3) than in females (35.4, 95% CI 32.4–38.4) p = 0.06. Key differences were found in the proportion of non-sporting injuries in patients under and over the age 40 (p = 0.001). The proportion of non-sporting injuries was significantly higher in females compared to males (25.9% female non-sporting injuries, versus 8.5% male; p = 0.02). Avulsions were more frequently reported in non-sporting activities (70.5%). The proportion of such injuries was notably higher in females, though this failed to meet significance (p = 0.124). Grouped by age category a bimodal distribution was noted, with the proportion of avulsions greater in younger (age <15) and older patients (age > 40) (p = 0.008). 86.8% of patients returned to pre-injury activity levels with a similar frequency across all study variables; age, activity (sporting vs non-sporting) and injury type (avulsion vs tear).

Conclusion

This review highlights a proportion of adults suffering grade 2 or 3 hamstring injuries from activities other than the classic sports trauma. The majority of these non-sporting injuries were avulsion injuries that clustered in older female and skeletally immature patients suggesting a potential link to bone mineral density.

Complete tear of the distal hamstring tendons in a professional football player: a case report and review of the literature

Semimembranosus tendon ruptures are rare and are often associated with involvement of the cruciate ligaments. We present a 24-year-old American football player who sustained a complete rupture of the semimembranosus tendon near its insertion associated with an avulsion fracture of the conjoint attachment of the lateral collateral ligament (LCL) and biceps femoris with intact cruciate ligaments and menisci during practice. At the scene he was immobilized and was taken to the hospital immediately. The diagnosis was reached after radiographs and an MRI of the affected knee were obtained. The semimembranosus tendon and the avulsion of the biceps femoris insertion were repaired surgically. We also review the literature for previously reported cases of distal hamstring injuries.

Surgical Management of Recurrent Musculotendinous Hamstring Injury in Professional Athletes

BACKGROUND

Hamstring injury is the most common muscular lesion in athletes. The conservative treatment is well described, and surgical management is often indicated for proximal tendinous avulsions. To our knowledge, no surgical treatment has been proposed for failure of conservative treatment in musculotendinous hamstring lesions.

PURPOSE

To describe the surgical management of proximal and distal hamstring musculotendinous junction lesions in professional athletes after failure of conservative treatment.

STUDY DESIGN

Case series; Level of evidence, 4.

METHODS

A consecutive series of 10 professional athletes, including 4 soccer players, 4 rugby players, and 2 handball players, underwent surgical intervention between October 2010 and June 2014 for the treatment of recurrent musculotendinous hamstring injuries. All athletes had failed at least 3 months of conservative treatment for a recurrent musculotendinous hamstring injury. Surgical resection of the musculotendinous scar tissue was performed using a longitudinal muscular suture. Lower Extremity Functional Scale (LEFS) and Marx scores were obtained at the 3-month follow-up, and a final phone interview was completed to determine recurrence of hamstring injury and return to previous level of play.

RESULTS

The mean age at surgery was 25.2 years (range, 19-35 years). The musculotendinous hamstring lesions involved 8 semitendinosus and 2 biceps femoris, with 6 injuries located proximally and 4 distally. Conservative treatment lasted a mean 5.1 months (range, 3-9 months) after last recurrence, and the patients had an average of 2.7 (range, 2-5) separate incidents of injury recurrence before surgical intervention was decided upon. At the 3-month follow-up, all patients had Marx activity scores of 16 and LEFS scores of 80. All 10 patients returned to the same level of play at a mean 3.4 months (range, 2-5 months). At a mean follow-up of 28.7 months, none of the athletes had suffered a recurrence. No surgical complication was encountered.

CONCLUSION

In cases of failed conservative treatment of musculotendinous hamstring lesions, surgical intervention may be a viable treatment option in professional athletes and allows the patient to return to the same level of play.

Distal Insertions of the Biceps Femoris: A Quantitative Analysis

Background:

Avulsion of the biceps femoris from the fibula and proximal tibia is encountered in clinical practice. While the anatomy of the primary posterolateral corner structures has been qualitatively and quantitatively described, a quantitative analysis regarding the insertions of the biceps femoris on the fibula and proximal tibia is lacking.

Purpose:

To quantitatively assess the insertions of the biceps femoris, fibular collateral ligament (FCL), and anterolateral ligament (ALL) on the fibula and proximal tibia as well as establish relationships among these structures and to pertinent surgical anatomy.

Study Design:

Descriptive laboratory study.

Methods:

Dissections were performed on 12 nonpaired, fresh-frozen cadaveric specimens identifying the biceps femoris, FCL, and ALL, and their insertions on the proximal tibia and fibula. The footprint areas, orientations, and distances from relevant osseous landmarks were measured using a 3-dimensional coordinate measurement device.

Results:

Dissection produced 6 easily identifiable and reproducible anatomic footprints. Tibial footprints included the insertion of the ALL and an insertion of the biceps femoris (TBF). Fibular footprints included the insertion of the FCL, a distal insertion of the biceps femoris (DBF), a medial footprint of the biceps femoris (MBF), and a proximal footprint of the biceps femoris (PBF). The mean area of these footprints (95% CI) was as follows: ALL, 53.0 mm² (38.4-67.6); TBF, 93.9 mm² (72.0-115.8); FCL, 86.8 mm² (72.3-101.2); DBF, 119 mm² (91.1-146.9); MBF, 46.8 mm² (29.0-64.5); and PBF, 215 mm² (192.4-237.5). The mean distance (95% CI) from the Gerdy tubercle to the center of the ALL footprint was 24.3 mm (21.6-27.0) and to the center of the TBF was 22.5 mm (21.0-24.0). The center of the DBF was 8.68 mm (7.0-10.3) from the anterior border of the fibula, the center of the FCL was 14.6 mm (12.5-16.7) from the anterior border of the fibula and 20.7 mm (19.0-22.4) from the tip of the fibular styloid, and the center of the PBF was 8.96 mm (8.2-9.7) from the tip of the fibular styloid.

Conclusion:

A tibial footprint, distal fibular footprint, medial fibular footprint, and proximal fibular footprint were all consistent components of the insertion of the biceps femoris. Consistent relationships existed between the biceps femoris and insertions of the ALL and FCL.

Clinical Relevance:

The size of these footprints and distances from pertinent surgical landmarks will guide repairs of biceps femoris avulsion injuries.

Clinical principles in the management of hamstring injuries

PURPOSE

Hamstring injuries are among the most common muscle injuries seen in sports clinical practice. This narrative review covers essential knowledge of hamstring injuries, ranging from strains to total proximal three-tendon ruptures. The primary aim is to provide basic information for clinicians and sports medicine therapists dealing with hamstring problems.

METHODS

In this review, existing literature of hamstring injuries was taken together. Emphasis was given to subjects less well covered in previous reviews, such as preventive measures, as well as the most relevant information needed in the treatment of these injuries.

RESULTS

Occasionally, symptoms remain after hamstring injuries which can be successfully treated with surgery. Knowledge of the effectiveness of preventive measures and nonsurgical and surgical treatment is limited by small studies of low evidence level.

CONCLUSIONS

Evidence-based treatment algorithms are not available. Larger studies of better quality with more concrete grading of hamstring tears are needed to improve knowledge in prevention and treatment of hamstring injuries.

LEVEL OF EVIDENCE

IV.

Diagnosis and prognosis of acute hamstring injuries in athletes

PURPOSE

Identification of the most relevant diagnostic and prognostic factors of physical examination and imaging of hamstring injuries in (elite) athletes.

METHODS

A literature search was conducted in MEDLINE and EMBASE for articles between 1950 and April 2011. A survey was distributed among the members of the European Society of Sports Traumatology, Knee Surgery and Arthroscopy, which focused on physical examination, prognosis, imaging and laboratory tests of hamstring injuries in (elite) athletes.

RESULTS

Medical history, inspection and palpation of the muscle bellies and imaging are most valuable at the initial assessment according to the literature. Experts considered medical history, posture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing, referred pain tests and imaging to be most important in the initial assessment of hamstring injuries. Magnetic resonance imaging (MRI) is preferred over ultrasonography and should take place within 3 days post-trauma. Important prognostic factors are injury grade, length of the muscle tear on MR images, MRI-negative injuries and trauma mechanism.

CONCLUSIONS

Posture and gait inspection, inspection and palpation of muscle bellies, range of motion tests, manual muscle testing and referred pain tests within 2 days post-trauma were identified as the most relevant diagnostic factors.

LEVEL OF EVIDENCE

Literature review and expert opinion, Level V.

Isolated rupture of biceps femoris tendon

Authors present a case of rupture of the distal end of the biceps femoris. Injuries at this site are relatively rare. Clinical assessment can be aided by instrumental examinations such as ultrasound and especially NMR. Delayed treatment because of erroneous diagnosis or failure of conservative therapy can result in proximal retraction and atrophy of the muscle belly, requiring more complex surgery. Despite the limited data in the literature, Authors favor immediate surgical treatment of both complete and partial injury of the biceps femoris tendon, particularly in a patient who requires a high level of function.

Posterior knee pain

Posterior knee pain is a common patient complaint. There are broad differential diagnoses of posterior knee pain ranging from common causes such as injury to the musculotendinous structures to less common causes such as osteochondroma. A precise understanding of knee anatomy, the physical examination, and of the differential diagnosis is needed to accurately evaluate and treat posterior knee pain. This article provides a review of the anatomy and important aspects of the history and physical examination when evaluating posterior knee pain. It concludes by discussing the causes and management of posterior knee pain.

Rupture of the conjoint tendon at the proximal musculotendinous junction of the biceps femoris long head: a case report

This case report describes a 20-year-old elite-level Australian Rules football player who suffered three unilateral hamstring injuries within a 2 month period. The first two episodes were managed conservatively. Magnetic resonance imaging following the third episode revealed full thickness disruption of the proximal musculotendinous junction of the biceps femoris long head and semitendinosus muscles and the common proximal (conjoint) tendon. The injury was subsequently surgically repaired. At 16 months following surgery, the player had successfully completed a full competitive season of elite-level Australian Rules football symptom free. Follow-up magnetic resonance imaging demonstrated the repaired tendon to be uniformly hypointense in keeping with reparative granulation tissue formation and restoration of normal muscle morphology. These findings are consistent with an intact repair. The case demonstrates that complete functional and radiological resolution is possible following surgical repair of significant hamstring musculotendinous junction tears.